1. Field of Invention
The present invention relates to an apparatus and a method used in the meat processing industry to separate a loin portion from carcass halves. More particularly, the present invention automatically follows the contour of the surface rib line to improve the quality of the cut separating the loin and the belly.
2. Description of the Related Art
In the field of meat processing, the quality of the separation of the loin and the belly greatly impacts the value of the two cuts of meat. Using pork processing as an example, the first step is to halve the carcass by cutting it into equal sides through the center of the backbone. Each carcass side is processed to remove the hindquarter and the forequarter. The remaining middle portion of the carcass contains the loin and belly. The carcass middle is cut to separate the loin and the belly.
Various devices have been developed that automate the process of separating the loin from the belly. One example of such a device is described in U.S. Pat. No. 5,234,371, issued to L. George Andre, et al., on Aug. 10, 1993. Another example is described in U.S. Pat. No. 5,295,898, issued to L. George Andre, et al., on Mar. 22, 1994. A still further example is described in U.S. Pat. No. 5,407,384, issued to Lawrence D. Boody, et al., on Apr. 18, 1995. U.S. Pat. No. 6,089,968 issued to Scott E. Andre, et al., on Jul. 18, 2000 describes a loin knife assembly having a blade that improves the ability to separate the belly and loin while cutting through the finger lean under the surface rib line. Finally, U.S. Pat. No. 6,547,658, issued to Lawrence D. Boody, et al., on Apr. 15, 2003 describes a dual-blade knife assembly for separating the loin from the belly. Each of these patents is instructive as to the general structure and operation of a machine for automatically recovering the loin, commonly referred to as a “loin puller.”
The size and weight of the belly are the determining factors in the valuing the belly cut in commodity bellies. This increases opportunity for achieving exposed lean while maintaining the minimum thickness of the belly edge. Visible lean meat on the belly increases the value of the cut. There is only a small portion of lean meat, referred to as the finger lean, located adjacent to the spare ribs on the belly. The finger lean has a depth of approximately one quarter-of an inch and is located approximately one half-inch below the surface rib line. The ideal cut separating the loin and the belly slices through the entire length of the finger lean, which increases the amount of exposed lean meat on the belly portion effectively increasing the useable size of the belly. Ultimately, the belly is trimmed until there is no more than approximately one half inch of fat between the edge of the belly and the start of the visible lean meat. The trimmings are greatly devalued to approximately one-tenth of the value that the trimmed portions would have if they remained part of the belly. A skilled human operator controlling the blade depth of a loin puller has an accuracy rate of approximately 85–90% when separating the loin and the belly through the finger lean. This results in 10–15% of the products being devalued. Further, it is extremely difficult to produce finger lean on product is thin, soft, or nearly frozen when manually pulling the loin. Accordingly, it is greatly desirable to improve the consistency and quality of the cut separating the loin and the belly to increase the amount of lean meat visible on the belly.